Shuttlecock

ABSTRACT

A shuttlecock having a base and a single piece injection molded plastics skirt is provided, which has flight characteristics and feel closely resembling feather shuttlecocks. The molded flared skirt has lower and upper portions, the upper portion being provided with a plurality of radially spaced stems of channel section, such as V-, C- or U- section. Intermediate the stems of the upper skirt there is provided a lattice structure which defines a plurality of slots set at an acute angle to the longitudinal axis of the shuttlecock. For attachment of the base to the skirt, the latter is provided with an integrally formed spigot formation having at least two spaced legs, each having a radially extending projection engageable with an annular groove formed internally of the base.

United States Patent 1 Robinson 451 Sept. 9, 1975 1 1 SHUTTLECOCK [22]Filed: June 11, 1973 [21] Appl. No.: 368,664

2,632,647 3/1953 Carlton, 273/106 A 3,313,543 4/1967 Carlton 273/106 A3,749,403 7/1973 Austin ct a1 273/1065 C FOREIGN PATENTS OR APPLICATIONS1,103,364 2/1968 United Kingdom 273/106 A United Kingdom 273/106 ACanada 273/106 A Primary Examiner-Paul E. Shapiro Attorney, Agent, orFirmMiller, Frailey & Prestia [57] ABSTRACT A shuttlecock having a baseand a single piece injection molded plastics skirt is provided, whichhas flight characteristics and feel closely resembling feathershuttlecocks. The molded flared skirt has lower and upper portions, theupper portion being provided with a plurality of radially spaced stemsof channel section, such as V-, C- or U- section. Intermediate the stemsof the upper skin there is provided a lattice structure which defines aplurality of slots set at an acute angle to the longitudinal axis of theshuttlecock. For attachment of the base to the skirt, the latter isprovided with an integrally formed spigot formation having at least twospaced legs, each having a radially extending projection engageable withan annular groove formed internally of the base.

7 Claims, 2 Drawing Figures PATENTED 1975 SHEET 1 [1F 2 SHUTTLECOCK Thisinvention relates to shuttlecocks, more particularly to shuttlecocks ofthe type having a plastics skirt.

Many shuttlecocks having a plastics skirt have been produced andproposed but in all the prior construe tions the flight characteristicsand feel during play have been very different from the characteristicsand feel of conventional feather shuttlecocks, As a result shuttlecockshaving a plastics skirt have been treated as inferior substitutes forfeather shuttlecocks and have not gained acceptance in the higherstandards of the game of badminton.

It is an object of the present invention to provide a shuttlecock havinga plastics skirt which has flight characteristics and fee] which moreclosely resemble the characteristics and feel of feather shuttlecocksthan plastics skirted shuttlecocks which are presently available.

According to one aspect of the present invention a shuttlecock skirtcomprises a lower skirt adjacent the base and an upper skirt remote fromthe base, at least the upper skirt being resilient and comprising aplurality of radially spaced longitudinally extending stems which are ofhollow section, i.e. channel section, over at least a portion of theirlength. The stems of the upper skirt may continue to form stem portionsin the lower skirt and, if desired, the stem portions in the lower skirtmay also be of channel section.

The number of radially spaced stems in the upper skirt is preferablyfrom 8 to 18 inclusive although it is particularly preferred to employl6 stems.

The stems in the upper skirt are preferably of hollow section over atleast 50% of their length, more preferably 75% of their length;advantageously they are of hollow section over substantially their wholelength.

The hollow or channel section of the stems may be C-, U- or V shape andthe shape of the section may vary along the length of the portion of thestem have a hollow section. It is desirable that a thickened zoneextends centrally along at least a portion of the length of the hollowportion each stem.

The stems in the upper skirt may be of substantially uniform width alongtheir length or may be tapered over at least a portion of their lengthso that the stem is narrower at a position more remote from the basethan at a position nearer the base.

The width of the stems, measured along the outer periphery thereof, maybe, for example, in the range 4 to mm, preferably 4 to 8 mm. A suitablewidth has been found to be 6 mm either extending along substantially thewhole length of the stem or tapering towards a width of about 4 mm atthe end of the stem remote from the base.

The stems in the upper skirt support a lattice structure intermediatethe stems. The lattice structure may be simple or complex but is ispreferred to provide sim ple lattice strips extending from one stem tothe next adjacent stem. These lattice strips may be connected togetherby one or more supporting strips extending generally parallel to thestems.

In order to facilitate folding of the shuttlecock under impact, which isnecessary to achieve the desired feel and sound, the lattice structureintermediate the stems may be fluted. Alternatively, the latticestructure may be discontinuous around the circumference of theshuttlecock, eg the portion of the lattice structure extending from onestem is not connected to the portion of the lattice structure of thenext adjacent stem. In this way, the shuttlecock can collapse underimpact in a manner similar to that of a conventional feathershuttlecock.

it is desirable that the lattice structure. whether it is continuous ordiscontinuous, defines a plurality of slots which are set at an acuteangle to the longitudinal axis of the shuttlecock. Advantageously, suchangled slots comprise at least 50% of the apertured area of the lat ticeStructure.

The use of such angled slots affords a very convenient way ofintroducing spin to the shuttlecock which is important in maintaining aconsistent and true flight path after the shuttlecock has been struck bya racket.

In certain constructions it may be possible to construct the lattice insuch a manner that the lattice strips present an aerofoil section to theair during flight so that the pressure on the lattice strips tends toexpand the skirt. Such an arrangement assists the shuttlecock to regainits normal shape quickly and also provides ad ditional air resistancewhich helps to improve the flight characteristics of the shuttlecock.

It is preferred that the skirt, at the extremity remote from the basehas an undulating profile in the plane of the skirt immediately beneaththe profile, Desirably, the undulating profile is arranged so that itsimulates the profile of a conventional shuttlecock having eitherpointed or rounded feather tips, although it is preferred to providepointed tips.

The area of the undulating profile portion, ie that area which lies moreremote from the base than a circumferential line parallel to the baseand passing through the lower extremities of the undulations, is atleast 50% imperforate. Preferably, the area is at least imperforate.

The presence of an undulating profile at the extremity of the skirtremote from the base has been found to improve the performance ofshuttlecocks relative to those having a straight extremity, particularlyas regards so-called net-play" which is very critical in the higherstandards of the game of badminton,

The skirts may be produced by any conventional technique utilised inproducing plastics objects, including moulding and fabricationtechniques. The preferred method is injection moulding since thisprocess is cmi nently suitable for large production runs.

The skirts may be produced from a variety of materi als. Wherefabrication techniques are employed plastics stems may be produced, egby injection moulding, and a lattice structure of plastics; naturalfibres; fabric, either woven or non-woven; paper; or similar materialsmay be secured thereto, either by adhesive or by the provision of asuitable formation on the stems for en gagement by the latticestructure.

Where the skirts are injection moulded in one step it is preferred touse a plastics material of relatively low specific gravity in order tokeep the weight of the skirt to a minimum. Materials which we have usedto pro duce shuttlecocks include, polyethylene, polypropylene, blends ofpolyethylene and polypropylene, blends of these polymers with EVA,nylons, particularly nylon 11, and ABS. It will be apparent that otherpolymers could be used, if desired. provided that they have thenecessary toughness and they satisfy the weight re quirements in thefinished shuttlecock.

Where a fluted skirt is to be produced a conical skirt may be mouldedinitially and then fluted in a subsequent forming operation. Such aprocess is described in British Patent Specification No 751,577. Ifdesired, the hollow section stems may also be produced using thistechnique.

It is, however, preferred that the skirt is produced in a singlemoulding operation. In this way, the hollow section stems can have amuch more precise shape than that obtained with a second formingoperation, and, in addition, the moulding-in of the hollow sectionaffords a more rigid structure which is desirable from the point of viewoffast recovery of shape after impact of the shuttlecock with a racket.

The thickness and width of the stems which may be used depends on theavailable weight of material, bearing in mind the number of stemsemployed, the weight of material in the lattice structure and the totalweight of material which will give the shuttlecock a satisfactoryturnover and flight,

Generally, the total weight of material available in the skirt is 2.00to 3.00 grams, preferably 2.00 to 2.70 grams, and more preferably 2.30to 2.50 grams. The precise weight chosen will depend upon thedistribution of the weight relative to the base.

The hollow section stems may be tapered from the centre to the sides inany plane which is perpendicular to the longitudinal axis of theshuttlecock skirt. The thickness at the centre line of the hollowsection stems in the upper skirt will generally have a maximum thicknessin the range 0.01 inches to 0.03 inches, preferably 0.01 to 0.02 inches,and a minimum thickness in the range 0.005 to 0.01 inches, preferably0.005 to 0.008 inches. The thickness at any point remote from the centreline will generally have a maximum thickness of 0.015 inches, preferably0.01 inches, and a minimum thickness in the range 0.005 to 0.01 inches,preferably to 0.008 inches.

Adjacent the longitudinal edges of the hollow section stems,particularly in the upper skirt there may be provided a rib which tendsto prevent tearing of the stem material and thus prolongs the usefullife of the shuttlecock. This rib will usually be of generally circularcrosssection and have a diameter of 0.01 to 0.20 inches mm.

The skirt is provided with a lower skirt which may comprise merelyextensions of the stems in the upper skirt or may be of differentconstruction. In one embodiment the lower skirt comprises a plurality ofstems of triangular cross-section connected at one end to a base ringand at the other end to a support ring which carries the upper skirt.

The lower skirt is connected to a formation which enables it to besecured to a separate base or, if desired, the base may be formedintegrally therewith. Where a separate base is employed the formationmay comprise a spigot formation which can locate in a socket in theseparate base. If desired, it may be secured thereto by a suitableadhesive.

Conveniently the spigot formation includes at least two legs, eachhaving a radially extending portion. Advantageously, an insert is shapedto fit between the legs to hold them against deformation, and to thisend the legs may include a shoulder portion to locate the insert.

The provision of a weight element in the base of a shuttlecock isgenerally necessary in order to achieve the desired speed. Differentweights are used to provide shuttlecocks of different speeds a range of'speeds being necessary to suit the various playing conditions which maybe encountered.

It is thus an aspect of this invention to provide an insert whichconstitutes, at least in part, a weight element of a shuttlecock.Inserts of various weights may be used to provide the different speedsof shuttlecock, or a standard insert may be used in conjunction with anauxiliary weight member.

Desirably the insert or auxiliary weight member is keyed e.g. byreference numerals or colour coding in such a way that the key isvisible through the bottom of the skirt when the skirt is attached tothe base. The reference numerals may correspond to the speed ratingsgenerally in use for conventional feather shuttlecocks, which generallylie in the range 78 to 85.

The invention is hereafter more particularly described with reference tothe accompanying drawings, in which:

FIG, 1 is a side elevation of one form of shuttlecock; FIG. 2 is a topview of the shuttlecock shown in FIG.

FIG. 3 is a side elevation of a further form of shuttlecock;

FIG. 4 is a cross-section of one form of spigot; and

HG. 5 is a base for use with a spigot formation.

FIG. 6 is a cross-sectional view taken as indicated by the lines 66 inFIG. 1.

The shuttlecock comprises a base 10 attached to a skirt 11 by a spigotformation (not shown) which is located in a corresponding socket in thebase 10.

The base 10 is moulded separately from the skirt from an expandedmaterial, such as expanded polyvinyl chloride and includes a socket toreceive the spigot formation on the skirt.

The skirt comprises an upper skirt l3 and a lower skirt 14 formedintegrally with one another and with the spigot formation by injectionmoulding.

The lower skirt 14 comprises 16 lower stems l5 radially distributedabout the longitudinal axis of the shuttlecock and supporting at theirends remote from the base a circumferential support ring 16. The lowerstems 15 are of triangular section and are tapered away from the base;at their lower, thicker, end they are connected by a base ring 17 whichextends both above and below the top of the base.

The upper skirt 14 comprises upper stem portions 19 which are alignedwith the lower stems 15 but are broader and thinner and are of V-sectionas can be seen in FIG. 2. The upper stern portions 19 may be of anysimilar channel-like hollow section, such as U-section or C-section, tothereby provide a relatively rigid structural effect to the upper stemsof the skirt 11.

The upper stem portions 19 terminate in pointed tips 20 which form partof the pointed upper edge 21 of the skirt which is shaped to simulatethat of a conventional feather shuttlecock having pointed feather tips.

The points of the upper edge 21 extend from an imaginary circumferentialline parallel with the top of the base and passing through the lowerextremities of the V-shaped slots intermediate the points.

The area of the points of the upper edge 21 is thus largely imperforate.

Intermediate the upper stem portions 19 there extends a fluted latticestructure which defines a plurality of parallel slots 23 set at an acuteangle to the longitudinal axis of the shuttlecock. A supporting rib 24is formed transverse to the slots 23.

A modified from of shuttlecock is shown in FIG. 3.

In this shuttlecock, the skirt is generally similar to that shown inFIGS. 1 and 2 but the lattice structure is not fluted and isdiscontinuous, the lattice strips being divided from each other alongthe lines 31. It will be appreciated that the lattice strips can, ifdesired, be offset from one another.

One way of attaching the shuttlecock to the base is shown in FIG. 4. Thespigot formation comprises four legs 50 having peripheral radialprojections 51. The legs are provided with a shoulder 52 to locate asolid cylindrical insert 53 which also serves as a weight ele ment.

The insert 53 is held against the shoulder by the base 54 when this isassembled with the skirt. The legs 50 locate in the cylindrical socket55 and the radial projections 51 locate in the circumferential groove56. The groove 56 is formed by contraction of the base onto the spigotformation.

This arrangement positively locates the weight element and prevents itsmovement during use, thus giving the shuttlecock a predictable andconsistent flight characteristic.

It will be apparent that the embodiments described above may be modifiedwithin the scope of the present invention.

What we claim is:

l. A shuttlecock skirt comprising a lower skirt and an upper skirt, theupper skirt being resilient and having a plurality of radially spacedlongitudinally extending stems which are of channel section over atleast a portion of their length and further having, intermediate saidstems, a lattice structure which defines a plurality of angled slotswhich serve to introduce spin when the shuttlecock is in flight, thelower skirt comprising a plurality of radially spaced longitudinallyextending stems of triangular section.

2. A skirt according to claim 1 in which the lattice structure isfluted.

3. A skirt according to claim 1 in which the extremity remote from thebase has an undulating profile in the plane of the skirt immediatelybeneath the profile.

4. A skirt according to claim 3 in which the area of the undulatingprofile portion is at least 50% imperforate.

5. A shuttlecock having a base and a single piece injection moldedplastics skirt providing flight characteristics and feel simulating theflight characteristics and feel of feather shuttlecocks, said skirtcomprising a. a lower skirt comprising a plurality of radially spacedlongitudinally extending stems of triangular configuration,

b. a resilient upper skirt, said upper skirt having i. a plurality ofradially spaced longitudinally extending stems which are of channelsection over at least a portion of their length and,

ii. intermediate said stems, a lattice structure which defines aplurality of angled slots which serve to introduce spin when theshuttlecock is in flight, and

c. a spigot affixed to the lower skirt for securing the base to theskirt.

6. A shuttlecock skirt comprising a. a lower skirt,

b. an upper skirt,

c. at least the upper skirt being resilient and having a plurality ofradially spaced longitudinally extending stems,

d. a lattice structure intermediate said stems, which define a pluralityof angled slots which serve to introduce spin when the shuttlecock is inflight, and

e. a spigot formation to permit attachment of a base, the spigotformation comprising at least two legs, each having a radially extendingportion.

7. A skirt according to claim 6 in which the legs include a shoulderportion to locate an insert.

1. A shuttlecock skirt comprising a lower skirt and an upper skirt, theupper skirt being resilient and having a plurality of radially spacedlongitudinally extending stems which are of channel section over atleast a portion of their length and further having, intermediate saidstems, a lattice structure which defines a plurality of angled slotswhich serve to introduce spin when the shuttlecock is in flight, thelower skirt comprising a plurality of radially spaced longitudinallyextending stems of triangular section.
 2. A skirt according to claim 1in which the lattice structure is fluted.
 3. A skirt according to claim1 in which the extremity remote from the base has an undulating profilein the plane of the skirt immediately beneath the profile.
 4. A skirtaccording to claim 3 in which the area of the undulating profile portionis at least 50% imperforate.
 5. A shuttlecock having a base and a singlepiece injection molded plastics skirt providing flight characteristicsand feel simulating the flight characteristics and feel of feathershuttlecocks, said skirt comprising a. a lower skirt comprising aplurality of radially spaced longitudinally extending stems oftriangular configuration, b. a resilient upper skirt, said upper skirthaving i. a plurality of radially spaced longitudinally extending stemswhich are of channel section over at least a portion of their lengthand, ii. intermediate said stems, a lattice structure which defines aplurality of angled slots which serve to introduce spin when theshuttlecock is in flight, and c. a spigot affixed to the lower skirt forsecuring the base to the skirt.
 6. A shuttlecock skirt comprising a. alower skirt, b. an upper skirt, c. at least the upper skirt beingresilient and having a plurality of radially spaced longitudinallyextending stems, d. a lattice structure intermediate said stems, whichdefine a plurality of angled slots which serve to introduce spin whenthe shuttlecock is in flight, and e. a spigot formation to permitattachment of a base, the spigot formation comprising at least two legs,each having a radially extending portion.
 7. A skirt according to claim6 in which the legs include a shoulder portion to locate an insert.